Le but de ce travail était de développer des sondes oligonucléotidiques liées à des marqueurs fluorescents émettant des signaux modifiés lors de l'hybridation avec des séquences complémentaires. Des conjugués ODNs-cyanines originaux ont été développés. L'influence de différents paramètres sur le signal fluorescent émis par la sonde ont été étudiés : position de liaisons des marqueurs à l'ODN (5'- ou internucléotidique), structure des cyanines, stéréochimie. Un nouveau réactif de phosphorylation des ODNs a été mis au point et utilisé pour la synthèse des conjugués marqués en position 5'.<br> D'autres conjugués comportant à leur extrémité 5' deux marqueurs identiques possédant des propriétés intercalantes : thiazole orange, pyrène ou pérylène ont été obtenus. Les interactions entre les deux marqueurs varient lors de l?hybridation de la sonde avec la séquence complémentaire, induisant une modification du signal fluorescent dont la nature et l'intensité dépendent du marqueur considéré

De nombreuses applications industrielles nécessitent le dépôt de films métalliques à la surface de polymères afin de conférer une fonction de conduction électrique à ces matériaux isolants. Cette étude a été motivée par la volonté de la société Radiall, dont une partie de l'activité concerne la réalisation de connecteurs à haute performance, de remplacer le procédé de métallisation par voie humide par un procédé de dépôt par voie sèche plasma. Le travail présenté ici porte ainsi sur l'étude du procédé de pulvérisation cathodique magnétron avec ionisation de la vapeur par plasma radiofréquence (RF-IPVD) pour le dépôt de couches minces de cuivre sur substrats de formes complexes en poly-sulfure de phénylène. Cette thèse regroupe d'une part les résultats concernant la métallisation des connecteurs et d'autre part l'analyse de la phase plasma. La validation du procédé RF-IPVD a comporté plusieurs étapes : i) le développement du traitement du polymère par plasma ICP avant dépôt du film de cuivre afin que l'adhérence satisfasse la norme ISO 2409. ii) la détermination des paramètres d'élaboration permettant d'optimiser la conductivité des films et leur conformité sur les substrats 3D. Ces travaux se sont concrétisés par la définition d'un réacteur pilote dans l'optique de réaliser la transposition à l'échelle industrielle du procédé RF-IPVD. Plusieurs études à caractère fondamental ont également été menées afin, d'une part, de comprendre les mécanismes régissant l'adhérence (analyses XPS) et ceux régissant la résistivité (analyses DRX). D'autre part, l'utilisation de divers diagnostics de la phase plasma ont été employés afin de comprendre les mécanismes de transfert d'énergie prenant place dans le milieu gazeux et responsables des propriétés des dépôts.

The aim of this thesis was to investigate carbon based molecular materials at first principles levels. Special attention has been paid to simulations of X-ray spectroscopies, including near edge X-ray absorption fine structure (NEXAFS), X-ray photoelectron, and X-ray emission spectroscopy, which can provide detailed information about core, occupied and unoccupied molecular orbitals of the systems under investigation. Theoretical calculations have helped to assign fine spectral structures in high resolution NEXAFS spectra of five azabenzenes (pyridine, pyrazine, pyrimidine, pyridazine and s-triazine), and to identify different local chemical environments among them. With the help of NEXAFS, the characters of important chemical bonds that might be responsible for the unique magnetic properties of the tetracyanoethylene compound has been revealed. Calculations have demonstrated that X-ray spectroscopies are powerful tools for isomer identification and structure determination of fullerenes and endohedral metallofullerenes. A joint experimental and theoretical study on metallofullerene Gd@C82 has firmly determined its equilibrium structure, in which the gadolinium atom lies above the hexagon on the C2 axis. It is found that the gadolinium atom could oscillate around its equilibrium position and that its oscillation amplitude increases with increasing temperature. In this thesis, several new computational schemes for large-scale systems have been proposed. Parallel implementation of a central insertion scheme (CIS) has been realized, which allows to effectively calculate electronic structures of very large systems, up to 150,000 electrons, at hybrid density functional theory levels. In comparison with traditional computational methods, CIS provides results with the same high accuracy but requires only a fraction of computational time. One of its applications is to calculate electronic structures of nanodiamond clusters varying from 0.76 nm (29 carbons) to 7.3 nm (20,959 carbons) in diameter, which enabled to resolve the long-standing debate about the validity of the quantum confinement model for nanodiamonds. Electronic structures and X-ray spectroscopies of a series of single-walled carbon nanotubes (SWCNTs) with different diameters and lengths have been calculated, which have made it possible to interpret the existing experimental results. / QC 20100727

Ce mémoire a trait à la nitruration du phosphure d'indium. Le phosphure d'indium est un semiconducteur III-V présentant un fort potentiel dans les domaines de la micro et de l'optoélectronique. La nitruration est un traitement de surface intervenant dans la croissance d'hétérostructures du type InN/InP.<br /> L'étude du processus de nitruration de l'InP(100) nécessite d'avoir une parfaite connaissance de l'état de la surface des substrats. Cette étude a été menée en employant différentes spectroscopies électroniques : spectroscopie des électrons Auger, des photoélectrons X, des pertes d'énergie des électrons et spectroscopie des électrons réfléchis élastiquement. Les effets du bombardement ionique -étape préalable à la nitruration- et du chauffage à une température égale à celle utilisée pour la nitruration ont été analysés. Le bombardement ionique entraîne la création de cristallites d'indium métallique qui subissent une transformation 3D-2D sous l'effet de la température.<br />La nitruration est réalisée dans un bâti ultravide. L'échantillon d'InP est exposé à un flux d'azote actif produit par une source à décharge haute tension. Les espèces azotées consomment les cristallites d'indium métallique précédemment créés par le bombardement ionique pour former de l'InN. Les effets du temps d'exposition au flux d'azote ainsi que de l'incidence du flux par rapport à la surface de l'échantillon ont été étudiés. Il s'est avéré que pour 40 minutes d'exposition sous une incidence rasante l'épaisseur des couches de nitrure était la plus importante. <br />L'étude d'un recuit des monocouches atomiques d'InN sur substrat d'InP à 450°C a montré le pouvoir passivant du film de nitrure puisque aucune détérioration du substrat n'a été constaté alors que la température de congruence de l'InP est de 370°C.

Η κατασκευή συσκευών μικροηλεκτρονικής με οργανικούς ημιαγωγούς όπως τρανζίστορς και φωτοεκπομποί δίοδοι οργανικών (FETs, OLEDs), αναπτύσσεται ταχύτατα τα τελευταία χρόνια. Οι φυσικές και χημικές αλληλεπιδράσεις που συμβαίνουν στις διεπιφάνειες των οργανικών με τα ηλεκτρόδια παίζουν καθοριστικό ρόλο στη λειτουργία τέτοιων συσκευών και επομένως η μελέτη της διεπιφανειακής ηλεκτρονικής δομής είναι σημαντική για την κατανόηση της λειτουργίας αυτών των διατάξεων. Στην παρούσα εργασία η ηλεκτρονική δομή των διεπιφανειών ενός συζυγιακού ολιγομερούς (Ooct-OPV5) με ανόργανα υποστρώματα, συγκεκριμένα το οξείδιο Ινδίου-Κασσιτέρου (ITO), τον πολυκρυσταλλικό Au, την επιφάνεια Si(111) (Si με προσμίξεις τύπου –Ν και -P) και υπέρλεπτα υμένια SiO2(1-5 nm) / Si(111), μελετήθηκε με φασματοσκοπίες φωτοηλεκτρονίων από ακτίνες –Χ και υπεριώδες (XPS, UPS). Το Ooct-OPV5 χρησιμοποιείται ως πρότυπο για το poly(p-phenylenevinylene) (PPV), ένα πολυμερές που έχει ήδη χρησιμοποιηθεί σε συσκευές OLEDs. Το ITO χρησιμοποιείται ως άνοδος στα OLEDs επειδή είναι διαφανές και έχει υψηλή ηλεκτρική αγωγιμότητα. Ο χρυσός είναι αδρανές υπόστρωμα που χρησιμοποιείται ως ηλεκτρόδιο στα FETs. Τέλος, η μελέτη διεπιφανειών του οργανικού με το Si παρουσιάζει ενδιαφέρον, προκειμένου να ενσωματωθούν οι οργανικοί ημιαγωγοί σε μικροηλεκτρονικές συσκευές με βάση το Si. Η μελέτη έγινε σε σύστημα υπερυψηλού κενού (UHV) με τις τεχνικές XPS και UPS. Τα υποστρώματα καθαρίζονταν in-situ με ιοντοβολή με Ar+ και θέρμανση. Ακολούθως γινόταν σταδιακή απόθεση του ολιγομερούς και παρασκευάζονταν υπέρλεπτα υμένια (πάχους ~10 nm) πάνω στα καθαρά υποστρώματα. Σε κάθε στάδιο της απόθεσης λαμβάνονταν τα φάσματα XPS του οργανικού και των υποστρωμάτων. Από την ανάλυση των φασμάτων αυτών προσδιορίζονται οι διεπιφανειακές αλληλεπιδράσεις και η μεταβολή της κάμψης των ζωνών των ημιαγώγιμων υλικών. Με τη φασματοσκοπία UPS μελετάται η ζώνη σθένους της διεπιφάνειας και μετράται η διεπιφανειακή διπολική στοιβάδα. Από το συνδυασμό των πειραματικών αποτελεσμάτων μπορούν να κατασκευάζονται σχηματικά διαγράμματα των ζωνών στις διεπιφάνειες. Με βάση τα πειραματικά αποτελέσματα καταλήγουμε στα εξής συμπεράσματα: Στις διεπιφάνειες του ολιγομερούς με το ITO, τον Au, το Si (τύπου -p) και το SiO2(1-1.8 nm)/Si(111) υπάρχει διεπιφανειακή διπολική στοιβάδα (eD) ενώ στη διεπιφάνεια Ooct-OPV5/ Si (τύπου -n) όχι. Αυτά τα διεπιφανειακά δίπολα σχετίζονται με την ύπαρξη διεπιφανειακών καταστάσεων και εξυπηρετούν τη μεταφορά φορτίου μεταξύ των υλικών που έρχονται σε επαφή στα πρώτα στάδια του σχηματισμού των διεπιφανειών. Κατά το σχηματισμό της διεπιφάνειας Ooct-OPV5/ Si (τύπου - p), το eD σχετίζεται με την αλληλεπίδραση των μορίων του ολιγομερούς με τις επιφανειακές καταστάσεις του Si. Στις διεπιφάνειες Ooct-OPV5/ με Au και Si, η μεταφορά φορτίου ολοκληρώνεται με τη μεταβολή της κάμψης των ζωνών του οργανικού υμενίου κατά ~0.20 eV. Τα φράγματα έγχυσης οπών (eΦbh) ή τα valence band offsets (ΔEV) καθορίστηκαν επίσης σε όλες τις περιπτώσεις. Στη διεπιφάνεια Ooct-OPV5 / Au το eΦbh μετρήθηκε 1.05 eV και επομένως ο Au είναι ακατάλληλο ηλεκτρόδιο για την έγχυση οπών. Το ITO αποδεικνύεται επίσης ακατάλληλο (eΦbh=1.45 eV) και η επιφάνειά του θα πρέπει να υφίσταται κατεργασία προκειμένου να χρησιμοποιείται ως άνοδος σε συσκευές OLEDs. Στην περίπτωση του Si, το valence band offset μεταξύ αυτού και του ολιγομερούς βρέθηκε ~0.4 eV. Η παραπέρα τροποποίηση της επιφάνειας του Si(111) με υπέρλεπτα υμένια SiO2 αυξάνει το ΔEV κατά ~0.2 eV. / The development of organic-based devices, like transistors and light emitting diodes (FETs, OLEDs), is progressing rapidly over the past few years. A great deal of the physics and chemistry that govern the performance of such devices occur at the interfaces between the organic components and the inorganic electrodes, making the study of the interfacial electronic properties essential. In this work, the electronic structure of the interface formed between a conjugated oligomer (Ooct-OPV5) and inorganic substrates, ιn particular indium-tin oxide (ITO), polycrystalline Au, the Si(111) surface (Si n- and p-doped), and ultrathin (1-5 nm) SiO2 films on Si(111), was studied by X-ray and Ultraviolet photoelectron spectroscopies (XPS, UPS). Ooct-OPV5 is a model for poly(p-phenylenevinylene) (PPV), a polymer that has already been used in OLEDs. ITO is the common anode used in OLEDs because of its transparency and high electrical conductivity. Gold was chosen due to its inert nature and because it is used as a source/drain in FETs. Finally, the study of organic/silicon structures is of great importance for the incorporation of organics in Si-based microelectronic systems. All XPS and UPS measurements were carried out in an ultrahigh vacuum (UHV) apparatus. All substrates were cleaned in-situ by Ar+ sputtering and annealing. High purity oligomer films of up to ~10 nm thickness were produced in-situ by stepwise deposition on the clean substrates. The evolution of the oligomer and substrate-related XPS peaks was followed during Ooct-OPV5 deposition on all substrates. Analysis of these spectra clarified the interfacial chemistry and band bending in the semiconducting materials. UPS spectroscopy is used for the determination of the valence band at the interface and the interfacial dipoles. The interfacial energy band diagrams were deduced in all cases from the combination of experimental results. Based on our experimental data we reached the following conclusions: Dipoles are formed at the interfaces of the oligomer with ITO, Au, Si (p-doped) and SiO2(1-1.8 nm)/Si(111), while the Ooct-OPV5/ Si (n-doped) interface is dipole free. These interface dipoles (eD) are related to the existence of interfacial states and serve for the charge transfer between the materials in contact at the initial stages of the interface formation. In the case of the Ooct-OPV5/ Si (p-doped) interface, eD is related to the interaction of the oligomer molecules with Si surface states. At the Ooct-OPV5/Au and Si interfaces, the charge transfer is completed with a band bending of ~0.20 eV in the oligomer film. The hole injection barriers (eΦbh) or valence band offsets (ΔEV) were also determined in all interfaces. This barrier was measured 1.05 eV at the Ooct-OPV5/ Au interface, and thus Au is inappropriate electrode for hole injection. ITO is also proved a poor hole-injecting electrode (eΦbh=1.45 eV), and thus its surface should be modified by treatments when used as an anode in OLEDs. On the other hand, the valence band offset between the Si substrate and the oligomer is measured ~0.4 eV. Modification of the Si(111) surface with ultra-thin SiO2 layers increases ΔEV by ~0.2 eV.

A crescente demanda de água nas cidades tem feito o homem buscar diferentes fontes de irrigação de culturas na agricultura, em se tratando de uma atividade que requer um grande montante de água. Neste contexto, o uso de efluente de esgoto tratado (EET), industrial ou doméstico, substituindo a água utilizada na irrigação de várias culturas, tem se mostrado ser uma medida promissora para preservá-la para o consumo humano.O propósito deste trabalho foi avaliar através de técnicas espectroscópicas (Infravermelho com Transformada de Fourier - FTIR, Espectroscopia de Fluorescência, Espectroscopia de Absorção de UV-Visível, Ressonância Paramagnética Eletrônica - RPE), as mudanças na matéria orgânica do solo (MOS) e ácidos húmicos (AH) extraídos de solo irrigado ou não com efluente de esgoto tratado, nas seguintes condições de irrigação: SI (sem irrigação com EET), 100 (irrigação com EET e umidade de solo na capacidade de campo) e 200 (irrigação com EET e umidade de solo 100% acima da capacidade de solo). Além dessas técnicas foi determinada a porcentagem de carbono e utilizada a espectroscopia de Fluorescência Induzida por Laser (FIL) para medir o grau de humificação de amostras de solo intacto, irrigados ou não com EET. As amostras de solo, sob cultura de cana-de-açúcar, foram coletadas em campo experimental situado em Lins-SP, em diferentes profundidades até 100 cm. As análises das amostras de solo demonstraram um decréscimo de porcentagem de carbono na faixa de 2 a 15% para as condições de irrigação com EET. O resultado é preocupante considerando tratar-se de solos com menos de 1% de conteúdo de carbono, e que tem com a aplicação do EET uma diminuição adicional na MOS, o que pode ser altamente limitante para a fertilidade e estrutura do solo. Os resultados obtidos por FIL para as mesmas amostras mostraram um aumento no grau de humificação variando de 9 a 30% nas áreas irrigadas com EET em relação às áreas não irrigadas com EET. Esse aumento do grau de humificação MOS é consistente com a diminuição de carbono do solo que mais provavelmente perde frações mais lábeis, permanecendo as mais recalcitrantes. Os espectros obtidos pela espectroscopia de FTIR para os AH analisados foram típicos, não mostrando diferença significativa, considerando as diferentes camadas de profundidade e irrigação ou não com EET. Os resultados obtidos por espectroscopia de fluorescência, usando três diferentes metodologias, de AH em solução mostraram, assim como a espectroscopia de FIL para amostras de solo, aumento no grau de humificação conforme aplicação de EET Assim como no caso da MOS, tal aumento no grau de humificação pode ser atribuído à degradação de frações de carbono mais lábeis e permanência das mais recalcitrantes dos ácidos húmicos analisados. Os resultados de razão E4/E6 (razão entre as intensidades de absorbância em 465 e 665 nm) para os AH analisados obtidos através da espectroscopia de absorção de UV-Visível denotaram decréscimo em seus valores nas camadas superficiais, comparando-se as três condições analisadas. Os resultados obtidos pela espectroscopia de RPE mostraram um aumento na concentração de RLS (radicais livres semiquinona) nos AH nas duas condições de irrigação, 100 e 200, sendo mais pronunciado na segunda. Corroborando com os resultados obtidos através das demais espectroscopias utilizadas, tal aumento da concentração de RLS provavelmente é oriundo de aumento de grau de humificação. Dessa forma, de acordo com os dados obtidos, o emprego de ET como fonte de irrigação em substituição à água, nas condições de solo analisadas são preocupantes, pois pode trazer limitações para a fertilidade e estrutura do solo, conforme evidenciado pelo decréscimo no conteúdo de MOS.Contudo, os experimentos devem ser continuados para confirmar e validar as tendências iniciais detectadas, bem como para buscar as alternativas de manejo dos solos e culturas para viabilizar a aplicação do EET em condições que sejam sustentáveis. / The increasing demand of water sources in the cities has done the man search for other different sources for irrigation of cultures in agricultural fields, hence it\'s an activity that demands a large amount of water. In this context, the use of treated sewage effluent (TSE), industrial or domestic, instead of water for irrigation of several cultures, has been shown to be a very promising way to save water for human consume.The purpose of this study is to evaluate by spectroscopic techniques (Fourier Transformed Infra-Red - FTIR, Fluorescence Spectroscopy, UV-Visible Spectroscopy and Electron Paramagnetic Resonance - EPR) the changes in the soil organic matter (SOM) and humic acids (HA) extracted from soils irrigated or not with treated sewage effluent, in the following concentrations of irrigation: SI (soil non-irrigated with TSE), 100 (soil irrigated with TSE and soil humidity in the same level of field capacity) and 200 (soil irrigated with TSE and soil humidity 100 % above field capacity). Besides these techniques, it was also determined the carbon percentage and used the Laser-Induced Fluorescence (LIF) spectroscopy to measure the degree of humification in samples of whole soil, irrigated or not with TSE. The soil samples analyzed in this study were collected from an experimental field in the city of Lins - SP, from a sugarcane culture soil, in the depth till 100 cm. The analysis of samples of whole soil showed a decrease in the carbon percentage in the range of 2 to 15% in the irrigation conditions comparing with the non - irrigated area. These results are preoccupying considering that it\'s a soil with less of 1% of carbon content, and has an additional decrease in the SOM when irrigated with TSE, what may cause limiting in the soil fertility and structure. The results obtained by LIF for the same samples, showed an increase in the humification degree varying from 9 to 30% in the irrigated area. This increase in the humification degree of soil organic matter (SOM) is consistent with carbon percentage decreasing in soil, which probably loses more labile fractions, remaining the most recalcitrant ones. The spectra obtained by the FTIR spectroscopy for HA analyzed were typical, not showing a significative difference, considering different layers of depth and treatment or not with TSE. The data obtained by fluorescence spectroscopy, using three different methodologies, of HA in solution showed, as well as the LIF spectroscopy for whole soils, an increment in the humification degree according to application of TSE. At the same way that happens with SOM, this increase in the humification degree may be attributed to degradation of carbon more labile fractions and remaining of the most recalcitrant ones in the humic acids. The results of E4/E6 ratio (ratio between the absorbance intensities at 465 and 665 nm) obtained by UV-Visible spectroscopy showed a decrease in the superficial layers, comparing the three conditions analyzed. The results obtained by the EPR spectroscopy showed an increase in the concentration of SFR (semiquinone free-radicals) in the HA with the increase of depth in the two conditions of irrigation, 100 and 200, being more pronunciated in the second treatment. Corroborating with the results obtained by the others spectroscopies, this increase in the SFR concentration probably may be attributed to the increase in the humification degree. In this manner, according with the obtained data, the use of TSE as source of irrigation replacing the water in the soil condition analyzed are preoccupying, hence it may cause limitations in soil fertility and structure, as evidenced by the decrease of the SOM content. However, the experiments must continue to confirm and validate the initials tendencies detected, and to search new alternatives for soil and culture tillage to make possible the TSE application in sustainable conditions.

Com a intenção de contribuir nas áreas de física aplicada a solos, agronomia e geologia, foi analisada a constituição mineralógica de três solos: Terra Roxa Estruturada Eutrófica da região de Piracicaba-SP, Cambissolo e Latossolo Vermelho-Escuro ambos da região de Ponta Grossa-PR, com a utilização da Difração de Raios X e o emprego do Método de Rietveld que é largamente utilizado na área de cristalografia de materiais policristalinos e recentemente, ainda com poucos trabalhos na literatura, utilizado em mineralogia. Estes solos foram coletados de vários horizontes. Cada horizonte foi fracionado em várias faixas de tamanhos de partículas, por peneiração foi obtida a fração areia grossa e por sedimentação as demais frações: areia fina, silte e argila, tendo sido obtidas 44 amostras. Devido à complexidade mineral de cada amostra, foram utilizadas também as seguintes técnicas espectroscópicas: Fluorescência de Raios, Emissão Atômica com Fonte de Plasma Induzido, lnfravermelho e Mossbauer, além de alguns testes preliminares com a Difração de Raios X que contribuíram de maneira significativa para o reconhecimento das fases presentes (minerais) permitindo que o Método de Rietveld pudesse fornecer, com segurança, dados quantitativos (porcentagem em massa) dos minerais presentes. De uma maneira geral, comparando os três solos estudados, pode-se afirmar que a grande diferença da Terra Roxa Estruturada Eutrófica é a maior presença dos argilominerais (caulinita, nacrita e haloisita), presença de ilmenita, com pouca quantidade de anatásio, rutílio e gibbsita. O Cambissolo mostra pequenas quantidades de hematita e goethita, e o grande diferencial do Latossolo Vermelho-¬Escuro é a presença marcante de gibbsita. Como critério para uma análise da aplicabilidade do Método de Rietveld em amostras de solo foram considerados os índices de qualidade RB (R-fator de Bragg) e RF (R-fator de estrutura) e os erros nas porcentagens em massa de cada mineral. Resultados bem sucedidos foram obtidos com o lote de amostras do Latossolo Vermelho-Escuro e com menos sucesso com os lotes de amostras dos outros dois solos. Desta forma, é possível utilizar o Método de Rietveld aliado à Difração de Raios X e às técnicas espectroscópicas para a caracterização mineralógica de solos. / The mineralogical constitution of three soils (Eutrophic Structured Dusky-¬Red Earth from the region of Piracicaba, São Paulo, Cambisol and Dark-Red Latosol both from the region Ponta Grossa, Paraná) was studied with the intention of contributing to the areas of physics applied to soil, agronomy and geology. The X-Ray Diffraction analysis, were done with the Rietveld Method. This method is widely employed for the crystalline characterization of polycrystalline materials and recently in mineralogical studies, yet with few works reported. Each soil was collected in several horizons. Each horizon was fractionated in several size range of particles: the coarse sand fraction was obtained by sieving and the fine sand, silt and clay fractions were obtained by sedimentation, in a total of 44 samples. Due to the mineral complexity of each sample, the following spectroscopics techniques were simultaneously used: X-ray Fluorescence, lnductively Coupled Plasma Atomic Emission Spectrometry, lnfrared and Mössbauer, besides some preliminary X-ray Diffraction tests that contributed in a significant way for the acknowledgement of the present phases (minerals) and the Rietveld Method supplied, accurate, quantitative data (in mass percentage) of present minerals. In a general way, the comparison of the three studied soils showed that Eutrophic Structured Dusky-Red Earth has the largest amount of clay minerals (kaolinite, nacrite, halloysite), and the presence of ilmenite, with small quantities of anatase, rutile and gibbsite. The Cambisol shows smaller amount of hematite and goethite, and the marked presence of gibbsite is the great difference of Dark-Red Latosol. A criterion for the applicability of Rietveld Method in soil samples was according to the values of the quality indices RB (R-Bragg factor) and RF (R-structure facto r) and mass percentage errors for each mineral. Good results were obtained for the Dark-Red Latosol\'s lot. For the other soils, those indices were obtained with less success. In this way, we have shown that it is possible to use the Rietveld Method associated with the X-Ray Diffraction and the spectroscopics techniques for the soils mineralogical characterization.

La thèse se déroule dans le cadre du projet ISOCEL qui vise à développer une nouvelle génération de cellules photovoltaïques. Plus précisément, ce travail se focalise sur la face arrière de ces panneaux. Il est primordiale que les capacités de protection aux intempéries de ces films, composés d’un mélange de poly(fluorure de vinylidène) (PVDF), de poly(méthacrylate de méthyle) (PMMA) et de dioxyde de titane (TiO2), soient assurés tout au long de la vie de la cellule. Ce travail de thèse a donc été de comprendre l’influence de la mise en œuvre de ces films sur leurs structures cristallines qui sont responsable de leur tenue mécanique, mais également de vérifier leurs évolutions pendant leurs vieillissements. Les films de PVDF/PMMA/TiO2 profitent du caractère cristallin du PVDF, et peuvent cristalliser en au moins quatre phases cristallines. Ils sont extrudés par soufflage de gaine, l’ensemble de la thèse portera donc sur cette technique d’extrusion. Une extrudeuse pilote a été utilisée pour réaliser les films de l’étude. Une partie de la thèse portera sur la caractérisation des différentes phases cristallines présentent dans les échantillons par spectroscopie Raman principalement, mais également par spectroscopie Infrarouge. Dans un deuxième temps, les méthodes d’analyses développées seront utilisées pour caractériser les films produits sous différentes conditions de soufflage de gaine, et les différences observées seront utilisées pour comprendre l’impact du procédé sur la cristallisation des films. Ces caractérisations passeront par des acquisitions de spectres Raman off line, at line et on line. Finalement, le vieillissement des films et l’impact des recuits sur leurs structures seront également approfondis, afin d’être capable de comprendre l’évolution des propriétés de ces films tout au long de la vie de la cellule photovoltaïque / This work is a part of the French project ISOCEL, which aims to build up a new generation of photovoltaic cell. More precisely, this study focuses on the backsheet of these panels, in order to ensure the weatherproof capacity of these films all along the lifetime of the cell. The main aim of this work is to understand the impact of the process conditions on the film crystalline structure. Indeed, this structure will govern the protective properties of the final backsheet. These films are made of a poly(vinylidene fluoride), poly(methyl methacrylate) and titanium dioxide (PVDF/PMMA/TiO2) blend, and created by a blown films extrusion process. PVDF has a semicrystalline structure which can take several forms depending on the manufacturing condition. A whole part of this work is devoted to the characterization of the film structure, especially with the Raman spectroscopy, which is the focus of the study. Different methods of spectral analysis are developed, such as the estimation of the crystalline phase ratio and spectra fitting. On the other hand, a pilot device are used to produce films with different process conditions. These films are characterized and the difference of structure are linked to the process conditions used. By this way, we show that the cooling condition have a strong influence on the film crystallization, notably on the form which can crystallize. On line Raman spectroscopy is used to characterize the film directly on the extruder, and thus understand the impact of the cooling condition

Zeolites are crystalline microporous solid acids composed of silica-rich frameworks with aliovalent Al heteroatoms substituted in crystallographically-distinct location sand arrangements, which generate anionic lattice charges that can be compensated by protons and extra framework metal cations or complexes that behave as catalytic active sites. Protons that charge-compensate Al are similar in Brønsted acid strength, yet differ in reactivity because their bound intermediates and transition states are stabilized by van der Waals interactions with confining microporous cavities, and by electrostatic interactions with proximal heteroatoms and adjacent protons. A diverse array of framework Al and extra framework H⁺site ensembles are ubiquitous in low-silica and low-symmetry zeolite frameworks (e.g., MFI, MOR), which cause measured turnover rates to reflect the reactivity-weighted average of contributions from each distinct site ensemble. The reactivity of distinct sites can be further masked by diffusion barriers often imparted by microporous domains and secondary reactions of primary products, which become increasingly prevalent as products encounter higher numbers of active sites during diffusion prior to egress from zeolite crystallites. Consequently,catalytic behavior often depends on zeolite material properties at orders-of-magnitude different length scales, which depend on the specific protocols used in their synthesis and crystallization.<div><br></div><div><div>In this work, CHA zeolites that contain only one symmetrically-distinct lattice site for Al substitution are used as model materials to decouple the effects of proton</div><div>location and proximity in vibrational spectra and turnover rates for acid catalysis. Interactions between proximal protons influence their equilibrium distribution among anionic lattice O atoms in AlO⁻_4/2tetrahedra, and result in temperature-dependent changes to vibrational frequencies and intensities of the asymmetric OH stretching region in infrared spectra measured experimentally and computed by density functional theory (DFT). Protolytic propane cracking and dehydrogenation, a catalytic probe reaction of the intrinsic reactivity of Brønsted acid protons, occur with turnover rates (748 K, per H⁺) that are an order-of-magnitude higher on paired protons than isolated protons, resulting from entropic benefits provided to late carbonium ion-pair transition states by proximal protons. These results indicate that cationic transition states can be stabilized entropically through multi-ion interactions with lattice anion and cation sites. Precise interpretation and quantification of the reactivity of different types and ensembles of Brønsted acid protons in zeolites requires that protolytic chemistry prevails in the absence of secondary active sites or other kinetically-relevant processes, a requirement generally met for alkane cracking but not dehydrogenation on H-form zeolites. Propane dehydrogenation activation energies vary widely (by >100 kJ mol⁻¹) among H-form zeolites of different structure (MFI, MOR, CHA) and composition (Si/Al = 10 – 140) because reactant-derived carbonaceous deposits form in situ and catalyze alkane dehydrogenation under non-oxidative conditions through hydride transfer pathways. Contributions of reactant-derived active sites to propane dehydrogenation rates are quantified through a series of transient and steady-state kinetic experiments with co-fed alkene and dihydrogen products, and are found to depend on gradients in product pressures that are present in integral reactors under non-ideal plug-flow hydrodynamics. Propane dehydrogenation rates collected at initial time-on-stream and in the presence of co-fed H₂ solely reflect protolytic reaction events and can be used to interpret differences in the reactivity of distinct proton sites and ensembles for alkane activation catalysis. The reaction conditions identified here can be used to remove or suppress the reactivity of carbonaceous active sites during catalysis, or to engineer the formation of organocatalysts on zeolite surfaces for selective dehydrogenation or hydride transfer reactions.</div></div><div><br></div><div><div>Synthetic strategies to decouple bulk and active site properties at disparate length scales, which are typically correlated in MFI zeolites crystallized hydrothermally, are developed by adding a second heteroatom and organic structure directing agent (SDA) to synthesis media. Crystallite size and morphology are independently varied from Al content by incorporating B heteroatoms into zeolitic frameworks, which generate protons that are catalytically irrelevant compared to those compensating Al, and NH₃ temperature-programmed desorption methods are developed to differentiate between these two types of proton sites. The siting of Al heteroatoms in distinct locations and ensembles is influenced by the decrease in cationic charge density among occluded SDAs, in cases where ethylenediamine is co-occluded with tetra-<i>n</i>-propylammonium cations. The co-occlusion of organic SDAs enables crystallizing MFI zeolites with different bulk properties but similar Al distributions, or with similar bulk properties and different Al distributions. MFI zeolites crystallized with these methods provide model materials that can be interrogated to decouple the effects of bulk and atomicscale properties on acid catalysis, and open opportunities to exploit these material properties by designing active site ensembles and crystallite diffusion properties for catalytic chemistries that depend on coupled reaction-transport phenomena.</div></div>

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